Tear gas is a chemical compound commonly used by police to control riot situations and evacuate buildings. The military uses tear gas to test soldiers' ability to put chemical warfare suits on in a timely manner. Tear gas is effective at stopping crowds and forcing people out of confined spaces because it causes extreme discomfort by irritating the eyes, skin and mucous membranes.
What Tear Gas Is
Tear gas is a blanket term that can be used for any of several chemical compounds that cause excessive tearing and irritation. Chloroacetophenone (CN), chlorobenzylidenemalononitrile (CS) and dibenzoxazepine (CR) are the three most commonly used tear gasses. These three chemical compounds have the same basic effects.
How It Works
Tear gas is generally released into the air as a gas or an aerosol. Tear gas often comes in a canister that is shot from a gun. The canister releases the gas as it flies through the air and bounces along the ground, spreading the gas over a wide area. Once the tear gas comes into contact with eyes, skin or mucous membranes, it causes severe irritation. Interestingly, tear gas has little or no effect on animals, which means that dogs and horses used by the military or police can continue to work unaffected in an area that has been tear-gassed.
Effects on Eyes and Skin
Tear gas gets its name from its most obvious and characteristic effect; it causes eye irritation and extreme tearing. The tearing and irritation are often so severe that people who have been exposed to tear gas cannot see properly and might not be able to keep their eyes open at all. It is common for eyes and eyelids to swell noticeably. Tear gas also irritates exposed skin, causing a burning sensation and a rash.
Effects on Nose and Mouth
When tear gas is inhaled, it causes irritation of the mucous membranes of the nose, throat and mouth. This causes uncontrollable drooling, an extremely runny nose, burning, itching and difficulty swallowing.
Effects on Lungs
Inhaled tear gas also affects the lungs. Gas in the lungs will cause tightness in the chest, shortness of breath, coughing, gagging and a choking sensation.
Exposure to tear gas might also cause nausea and vomiting, especially in cases of prolonged exposure or when a large amount of tear gas is inhaled. Prolonged exposure--that is, over an hour--can cause serious damage to the eyes, skin and lungs. Extreme tear gas exposure of this type can cause glaucoma from the swelling of the eyes, blindness, severe burns on the skin and respiratory arrest. It is possible to die from tear gas exposure, usually caused by respiratory failure. People who have heart conditions, asthma or other breathing problems are especially susceptible to death from tear gas exposure.
Generally, the effects of tear gas wear off in 30 minutes to an hour. Treatment for the symptoms of tear gas exposure includes rinsing the affected areas with water, burn management with salves and bandages and the use of bronchodilators that are used for asthma attacks.